• Title/Summary/Keyword: Response function

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The Multiple Traveling Purchaser Problem for Minimizing Logistics Response Time in Wartime (전시 군수반응시간 최소화를 위한 복수 순회구매자 문제)

  • Choi, Myung-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.3
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    • pp.431-437
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    • 2010
  • It's strongly needed to minimize the logistics response time for supporting military operations in wartime. In this paper, we suggest the ILP formulation for minimizing logistics response time in wartime. Main structure of this formulation is based on the traveling purchaser problem(TPP) which is a generalized form of the well-known traveling salesman problem(TSP). In the case of general TPP, objective function is to minimize the sum of traveling cost and purchase cost. But, in this study, objective function is to minimize traveling cost only. That's why it's more important to minimize traveling cost(time or distance) than purchase cost in wartime. We find out optimal solution of this problem by using ILOG OPL STUDIO(CPLEX v.11.1) and do the sensitive analysis about computing time according to number of operated vehicles.

FRF Distortion Caused by Exponential Window Function on Impact Hammer Testing and Its Solution (지수창함수를 사용한 임팩트햄머 실험에서 주파수응답함수의 왜곡과 개선책)

  • 안세진;정의봉
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.5
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    • pp.334-340
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    • 2003
  • Exponential window function Is widely used In impact hammer testing to reduce leakage error as well as to get a good S/N ratio. The larger its decaying rate is, the more effectively the leakage errors are reduced. But if the decay rate of the exponential window is too large, the FRF is distorted. And the modal parameters of the system can not be exactly identified by modal analysis technique. Therefore, it is a difficult problem to determine proper decay rate in impact hammer testing. In this paper, amount of the FRF distortion caused by exponential window is theoretically uncovered. A new circle fitting method is also proposed so that the modal parameters are directly extracted from impulse response spectrum distorted by the exponential-windowed impulse response data. The results by the conventional and proposed circle fitting method are compared through a numerical example.

The Internal Structure of an Identification Function in Korean Lexical Pitch Accent in North Kyungsang Dialect

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.5 no.1
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    • pp.91-98
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    • 2013
  • This paper investigated Korean prosody as it relates to graded internal structure in an identification function. Within Korean prosody, variants regarded as dialectal variations can appear as different prosodic scales, which contain the range of within-category variations. The current experiment was intended to show how the prosodic scale corresponding to the range of within-category differences relates to f0 contours for speakers of two Korean dialects, North Kyungsang and South Cholla. In an identification task, participants responded by selecting an item from two answer choices. The probability of choosing the correct response from the two choices was computed by a logistic regression analysis using intercepts and slopes. That is, the correct response between two choices was used to show a linear line with an s-shape presentation. In this paper, to investigate the graded internal structure of labeling, 25%, 50%, and 75% of predicted probability were assessed. Listeners from North Kyungsang showed progressive variations, whereas listeners from South Cholla revealed random patterns in the internal structure of the identification function. In this paper, the results were plotted using scatterplot graphs, applying the range of within-category variation and predicted probability obtained from the logistic regression analyses. The scatterplot graphs showed the different degree of the responses for f0 scales (i.e., variations within categories). The results demonstrate that the gradient structures of native pitch accent users become more progressive in response to f0 scales.

Direct Measurement of Chamber Response Function and Its Application to Radiation Dose Distribution Dosimetry (전리함 반응 함수의 직접 측정과 이를 이용한 방사선의 실제선량 분포측정)

  • Lee Sang Hoon;Cho Byung Chul;Kim Jong Hoon;Choi Eun Kyung;Kwon Soo Il;Chang Hyesook;Yi Byong Yong
    • Radiation Oncology Journal
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    • v.15 no.1
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    • pp.65-69
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    • 1997
  • Purpose : To obtain the actual dose distribution from measured data by doconvolution method using the measured ion chamber response function. Materials and Methods : The chamber response functions for 2 ionization chambers (diameter 5mm, 6.4mm) were measured. and dose Profiles were measured for $10{\times}20cm^2$ field size using two different detectors. The deconvolution of chamber response function from the measured data were performed for these Profiles. The same procedures were repeated for 4MV, 6MV and 1 SMV photon energies. Results : Different dose Profiles were obtained for the same field with the chambers which have the different response functions. Nearly the same results could be obtained with deconvolution for the profiles from various detectors. Conclusion : The effect of the chamber response function can be extracted by deconvolution method. Deconvolved dose profile using various ionization chambers gave better dose distributions. Technical improvements are needed for practical application.

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A Graphical Method for Evaluating the Effect of Outliers, Missing Observations, and Design Augmentation in the Slope Estimation of Response Surface Designs

  • Jang, Dae-Heung;Park, Sang-Hyun
    • Journal of Korean Society for Quality Management
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    • v.19 no.2
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    • pp.17-39
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    • 1991
  • In many application of response surface methodology, good estimation of the derivatives of the response function may be as important or perhaps more important than estimation of mean response. Using a graphical method, we have studied the effect of outliers, missing observations, and design augmentation with respect to the slope estimation in the response surf ace designs.

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Study of transient response in dielectric microstrip line with opto-microwave pulses

  • Wang, Xue;Kim, Ji-Hyoung;Yun, Ji-Hun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.2
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    • pp.63-68
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    • 2009
  • We study on the transient response in non-uniform microstrip lines with optically controlled microwave pulses. The transient response of the microwave pulses in plasma layer has been evaluated by reflection function of dielectric microstrip lines. The variation of characteristic response in plasma layer with localized pulses has been evaluated analytically. Reflection the change of the reflection amplitude has been observed.

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Response surface methodology based multi-objective optimization of tuned mass damper for jacket supported offshore wind turbine

  • Rahman, Mohammad S.;Islam, Mohammad S.;Do, Jeongyun;Kim, Dookie
    • Structural Engineering and Mechanics
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    • v.63 no.3
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    • pp.303-315
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    • 2017
  • This paper presents a review on getting a Weighted Multi-Objective Optimization (WMO) of Tuned Mass Damper (TMD) parameters based on Response Surface Methodology (RSM) coupled central composite design and Weighted Desirability Function (WDF) to attenuate the earthquake vibration of a jacket supported Offshore Wind Turbine (OWT). To optimize the parameters (stiffness and damping coefficient) of damper, the frequency ratio and damping ratio were considered as a design variable and the top displacement and frequency response were considered as objective functions. The optimization has been carried out under only El Centro earthquake results and after obtained the optimal parameters, more two earthquakes (California and Northridge) has been performed to investigate the performance of optimal damper. The obtained results also compared with the different conventional TMD's designed by Den Hartog's, Sadek et al.'s and Warburton's method. From the results, it was found that the optimal TMD based on RSM shows better response than the conventional damper. It is concluded that the proposed response model offers an efficient approach regarding the TMD optimization.

Probabilistic Distribution of Displacement Response of Frictionally Damped Structures under Earthquake Loads (지진하중을 받는 마찰형 감쇠를 갖는 구조물의 변위 응답 확률 분포)

  • Lee, Sang-Hyun;Park, Ji-Hun;Youn, Kyung-Jo;Min, Kyung-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.639-644
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    • 2007
  • The accurate peak response estimation of a seismically excited structure with frictional damping system(FDS) is very difficult since the structure with FDS shows nonlinear behavior dependent on the structural period, loading characteristics, and relative magnitude between the frictional force and the excitation load. Previous studies have estimated that by replacing a nonlinear system with an equivalent linear one or by employing the response spectrum obtained based on nonlinear time history and statistical analysis. In the case that on earthquake load is defined with probabilistic characteristics, the corresponding response of the structure with FDS has probabilistic distribution. In this study, nonlinear time history analyses were performed for the structure with FDS subjected to artificial earthquake loads generated using Kanai-Tajimi filter. An equation for the probability density function (PDF) of the displacement response is proposed by adapting the PDF of the normal distribution. Finally, coefficients of the proposed PDF is obtained by regression analysis of the statistical distribution of the time history responses. Finally, the correlation between PDFs and statistical response distribution is presented.

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A linear model for structures with Tuned Mass Dampers

  • Ricciardelli, Francesco
    • Wind and Structures
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    • v.2 no.3
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    • pp.151-171
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    • 1999
  • In its 90 years of life, the Tuned Mass Damper have found application in many fields of engineering as a vibration reducing device. The evolution of the theory of TMDs is briefly outlined in the paper. A generalised mathematical linear model for the analysis of the response of line-like structures with TMDs is presented. The system matrices of the system including the TMDs are written in the state space as a function of the mean wind speed. The stability of the system can be analysed and the Power Spectral Density Function of any response parameter calculated, taking into account an arbitrary number of modes of vibration as well as an arbitrary number of TMDs, for any given PSDF of the excitation. The procedure can be used to optimise the number, position and mechanical properties of the damping devices, with respect to any response parameter. Due to the stationarity of the excitation, the method is well suited to structures subjected to the wind action. In particular the procedure allows the calculation of the onset galloping wind speed and the response to buffeting, and a linearisation of the aeroelastic behaviour allows its use also for the evaluation of the response to vortex shedding. Finally three examples illustrate the suggested procedure.